CD case and syringe is fine.

Unless it's a serious build (where your comp-ratio is a modification) use a pipette or burette and some thicker clear glass. But to check and confirm it's fine, I use a big syringe and some acrylic to quickly check cc's.

Some also use food dye to help spot bubbles or coloured fluid like kero. The plates I use also have a smaller venting hole (which you can also calculate the volume for assuming you know plate thickness and bore size).